Battle Calculators

The AE system for determining the outcome of a battle is fairly complicated because it not only considers ship types, numbers, and related tech levels, but also includes a process of scrolling through both fleets while pitting every attacking ship against every defending unit, turret, and ring.
There are other variables included as well such as Command Centers, Tactical or Defense Commander levels, and something called cross-shield effects.

At the completion of an attack some ships are destroyed, some are damaged, and some are seemingly untouched. It frequently confuses players who thought that they had a sure win situation.

There are several "Battle Calculator" programs available. Most give you a reasonably close battle outcome result PROVIDED you enter all the relevant information. It is not clear if any of them use exactly the same calculations as the game itself.

The process of calculating the outcome of a battle is something like this -

Power of fleet= (number of unit X basic power X (1+power modifier from tech/100*)-shield X (1+shield modifier from tech/100**)

Defense of fleet= (number of unit X basic armour X (1+armour modifier from tech/100*)
This takes into account the whole shield value of the opponents fleet thus the total damage is much lower than the theoretical damage before shields.

The actual calculation begins at the lower units, usually fighters, and proceeds up to Death Stars. If the attacker's power can overcome the defenders armour the defender dies, and the attacker proceeds to the next defender.

It is possible for multiple players to be parked over a single base, and any of them may attack any of the others (you cannot attack a guild mate). However, there is only ONE battle at a time, initiated by a single attacker and against a single defender. Remember that the base defenses (turrets, CC's etc.) ONLY work with the base owner. Other fleets are "naked".